1. Field of the Invention
This invention relates to coated masonry building units, coating compositions, therefor, and coated masonry building units composed of ceramic coated quartz particles which when combined with polymerizable polyester resins provide cast articles which exhibit resistance to fading, staining and pigmentation degradation in exterior applications.
2. Description of the Prior Art
It has been recognized in the prior art that ceramic coated mineral particles may be employed to provide pigmentation and color in various resinous coatings and compositions. In Lea, U.S. Pat. No. 3,562,076, translucent or transparent base rock having a pigmented ceramic coating was employed for flooring compositions with colored decorative inserts which when subjected to wear remain color stable. Ceramic coated materials such as quartz, quartzite or igneous rock have been coated with ceramic materials and employed in coating compositions employing fused hydroplastic clay (Jewitt, U.S. Pat. No. 2,379,358) or combined with pigments to provide various roofing materials (Buzzell, U.S. Pat. No. 2,614,051).
Various organic polymeric resins have been employed as binders for ceramic coated particles for tile compositions such as, for example, Lea, U.S. Pat. No. 3,562,076, which as discussed, prevented discoloration resulting from abrasion.
The basic patent on the use of polyester as coatings for masonry units is Sergovic U.S. Pat. No. 2,751,775.
In Sergovic, U.S. Pat. No. 3,328,231, a coated masonry building block was made of a cured composition of an unsaturated polyester resin and sand in which the sand comprises at least 50% by weight of the coating composition. The unsaturated polyester resin is derived from a reaction between a dicarboxylic acid, e.g., phthalic, maleic, fumaric, adipic, pimelic, suberic, itaconic, citraconic, succinic acids, hydrides and polyhydric alcohol, e.g., ethylene glycol, diethylene glycol and propylene glycol. There is also present an unsaturated monomer such as methyl methacrylate, styrene, diallyl phthalate, t-butyl styrene, alpha-methyl styrene. In Sergovic, U.S. Pat. No. 4,031,289, coated masonry building blocks and articles and compositions therefor were provided which employed various pigments in combination with various resinous compositions to provide stain resistance to discoloration (blushing) when subjected to high moisture conditions for long periods. The entire disclosure of Sergovic U.S. Pat. Nos. 4,031,289; 3,328,231 and 2,751,775, are hereby incorporated by reference and relied upon.
Such pigmented surfaces while highly impervious to moisture have in the case of some pigments faded and discolored in environmental conditions involving repeated and protracted periods of exposure to bright sunlight. The problems of color losses are particularly apparent in exterior applications of tile where sharp contrasts exist between shaded and exposed areas of tiles. Consequently, it is an object of the present invention to provide a building composition which may be employed in the external applications subjected to protracted and sharp contrasts of sunlight and shade and withstand not only the dirt and water generally encountered under such environmental conditions but at the same time retain its color consistency and vitality under such conditions. Likewise, the present invention is of benefit in both interior and exterior applications, since it provides a coating with a translucent three dimensional coloring system that offers a completely different appearance and range of colors than is possible using the prior art.